In a recent interview with The Post, John Lithgow recounted that “Love Is Strange” director Ira Sachs often told him and co-star Alfred Molina that he was very glad he hired actors “who, half the time, are comic actors. Because we do bring a little humor” to the project. And they do.

“Saturday Night Live” alums Bill Hader and Kristen Wiig sharpen that fine point with their bittersweet, touchingly true turns in the indie “The Skeleton Twins.” This tale of sibling reconciliation and reckoning proves just how intimately bound laughter and tears can be.

Hader and Wiig are utterly believable as twins Milo and Maggie. Though a flashback to their childhood might throw you: Milo is dressed in drag for Halloween. Their beloved father christened them the Gruesome Twosome when they were children. His favorite holiday was Halloween, and the memory of that — and more — haunts them still.

That recurring flashback makes it clear how close they once were. A phone call at the start of the movie makes it clear how distant they have become.

The unexpected call — both perfectly timed and terrifically disruptive — brings Maggie to a hospital in Los Angeles. The pair haven’t spoken in a decade and now live on opposite coasts.

Beginning with inviting Milo to recuperate at her home in New York, Maggie struggles to do the right thing. She’s not entirely successful and it pains her.

Milo is in a cynical, unfiltered mood. Part of this is just his way. Part of this is predicated on an unexpected return to the hometown he fled angling to become an actor.

His barbed sense of humor makes his narcissism more exasperating than unbearable. Well, almost. Throughout much of Milo and Maggie’s awkward reunion, we know something is ailing his sister. Stuck in his misery, he has no idea and seemingly zero interest in asking her how she is as opposed to judging how she’s doing.

For instance, it’s easy for Milo to smirk at Maggie’s husband, Lance. Luke Wilson is in rare, but not unfamiliar, form as the kind, upbeat pup of a man who’s thrilled that he and Maggie are trying to have a baby.

More generous than Milo, more aware than Maggie, “The Skeleton Twins” takes smartly paced care in showing how differently damaged each has been by their shared past.

Ty Burrell of the ABC hit “Modern Family,” brings a repressed quiet to Rich, Milo’s former high school English teacher.

It’s just the steepest challenge met in a film that imagines a suicide note that begins with “To Whom It May Concern” and ends with a smiley face. And sends a mother (Joanna Gleason) to visit her children bearing plenty of New Age platitudes about compassion and not a nourishing drop of it for her offspring.

Director Craig Johnson and Mark Heyman’s script won the Waldo Salt Screenwriting Prize at January’s Sundance Film Festival. For good reason: “The Skeleton Twins” is a lovingly calibrated mix of heartbreak and hopefulness, guilt and the will to do better.